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When Your Water Breaks Too Soon: Understanding PROM
In most pregnancies, the amniotic sac breaks naturally during labour. The release of fluid lubricates the birth canal and signals that labour is progressing. But in about 8–10% of term pregnancies, the membranes rupture before labour begins, that’s PROM.
If this occurs before 37 weeks, it’s called preterm prelabour rupture of membranes (PPROM). PPROM accounts for nearly one-third of preterm births, according to the American Journal of Obstetrics and Gynaecology and FOGSI-referenced studies.
The amniotic fluid protects your baby from infection, cushions movement, and supports the development of the lungs and digestive system. Once that sac ruptures early, your baby loses this layer of protection, and bacteria from the vagina can travel upward. That’s why even a small leak warrants medical attention.
Why the Timing Matters
PROM isn’t just about when your water breaks; it’s about what happens next.- Risk of infection: Without the amniotic sac intact, there’s a higher chance of chorioamnionitis, an infection of the amniotic fluid and membranes that can endanger both mother and baby.
- Labour onset: Around 90% of women with PROM at term will go into labour naturally within 24 hours. Doctors may induce labour if contractions don’t begin on their own.
- For preterm pregnancies: The earlier it happens, the greater the risk of complications like preterm birth, underdeveloped lungs, or cord compression.
Common Causes and Risk Factors
PROM can occur without a clear cause, but several factors are known to weaken the membranes or increase the likelihood of rupture:
- Infection: Bacterial vaginosis, urinary tract infections, or sexually transmitted infections can weaken the amniotic sac.
- Cervical insufficiency: A weakened or shortened cervix may place extra pressure on the membranes.
- Multiple pregnancy: Carrying twins or more increases uterine stretching.
- Polyhydramnios (excess amniotic fluid): The sac stretches beyond its normal capacity.
- Previous PROM or preterm birth: A history of early rupture raises the risk in subsequent pregnancies.
- Smoking: Studies show nicotine exposure damages collagen in the membranes, making them more likely to tear.
- Frequent vaginal exams or procedures: Invasive testing late in pregnancy can sometimes introduce infection.
Signs That Your Membranes May Have Ruptured
One of the biggest sources of confusion is differentiating between urine leakage, discharge, and amniotic fluid. Here’s how you can tell the difference:
- Amniotic fluid: Usually clear, pale, and odourless, like diluted coconut water. It can gush suddenly or trickle continuously.
- Urine: Has a strong smell and typically stops after emptying the bladder.
- Discharge: Thick or sticky, not watery or soaking.
- A constant wetness in your underwear or bed linen.
- Fluid leakage when you stand or change position.
- Mild lower abdominal pressure or cramps.
- Rarely, a pinkish tinge if the cervix is starting to open.
- A green or brown tinge in the fluid (possible meconium).
- Fever, chills, or foul odour (signs of infection).
- Reduced baby movement.
- Pain, contractions, or bleeding.
Diagnosis: How Doctors Confirm PROM
Your doctor will typically begin with a speculum examination, a sterile visual check to confirm if fluid is pooling in the vagina. Unlike old myths, digital vaginal exams are usually avoided until necessary because they can increase infection risk.
Common diagnostic tests include:
- Nitrazine test: Checks pH; amniotic fluid is more alkaline than normal vaginal fluid.
- Fern test: A sample of fluid is dried on a slide and examined under a microscope; amniotic fluid forms a fern-like pattern.
- Ultrasound: Assesses amniotic fluid levels and foetal well-being.
- AmniSure or ROM-Plus tests: Used in some hospitals for higher accuracy, these detect specific amniotic proteins.
Treatment and Management
Management depends largely on how far along you are in your pregnancy and whether infection or foetal distress is present.
If you are at or near term (37 weeks or later):
- Labour is usually induced within 24 hours if contractions haven’t started naturally.
- Doctors may perform continuous foetal monitoring to check your baby’s heart rate.
- You’ll likely receive prophylactic antibiotics to reduce infection risk.
If you’re preterm (before 37 weeks):
- Hospitalisation is often required for observation and infection prevention.
- Corticosteroids (such as betamethasone) may be given to speed up foetal lung development.
- Magnesium sulphate may be administered if delivery before 32 weeks seems likely to protect the baby’s brain.
- Antibiotic therapy (commonly erythromycin or ampicillin) is recommended by WHO and NHS guidelines to prolong latency, the time between rupture and labour.
When immediate delivery is necessary:
- Signs of chorioamnionitis (maternal fever, uterine tenderness, or foul odour).
- Foetal distress on monitoring.
- Heavy bleeding or cord prolapse.
What Happens If It Happens Too Early
When PROM occurs before 34 weeks (PPROM), decisions become more complex. Doctors assess the risks of infection against the benefits of continuing pregnancy.
Potential complications include:
- Preterm labour and delivery.
- Infection: Both maternal sepsis and neonatal infection risk increase.
- Umbilical cord compression: Can affect oxygen supply to the baby.
- Pulmonary hypoplasia: If rupture happens very early (<24 weeks), the baby’s lungs may not develop fully.
Doctors may also advise pelvic rest, avoiding intercourse, tampon use, or internal examinations unless medically required. Whether it happens at 40 weeks or 34, your awareness and prompt action can make a decisive difference.
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FAQs on PROM (Pre-labour Rupture of Membranes) in Pregnancy: What Does It Mean for You
- How is PROM different from PPROM?
PROM happens at or after 37 weeks, before labour starts. PPROM occurs before 37 weeks and needs specialised management to prevent preterm birth and infection. - Can I still have a normal delivery after PROM?
Yes. If you’re full-term and your baby is fine, most women go into labour naturally or after induction and deliver vaginally. - What causes the water bag to break early?
Often it’s due to infection, uterine over-distension, or cervical weakness. In many cases, the cause remains unknown. - How long after PROM does labour start?
In about 9 out of 10 term pregnancies, labour starts within 24 hours. Doctors may induce labour if it doesn’t start naturally to prevent infection.